-1 and 3 over 4 multiplied by -1 and 2 over 5, I got 1 and 6 over 20 and my calculator says 1 and 9 over 20, how did it get that answer? I am confused
The easiest thing to do to solve these kind of problems is to turn it into one fraction, so you don't have a mixed fraction.
$\displaystyle -1\frac{3}{4} = \frac{-7}{4}$
Once you have done that, just multiply the numerator by the numerator and the denominator by the denominator.
$\displaystyle \frac{a}{b} \times \frac{c}{d} = \frac{a \times c}{b \times d}$
And then you will get your answer.